The present invention is generally directed to matrix type font printers capable of graphics printing and in particular to a matrix type font printer capable of printing high speed and quality bit addressable graphics.
Conventional serial printers with a matrix type font utilize the puntuation mark "." (the period), which is included as one of the font characters for printing graphics. The period is printed either in successive spaces or partially superimposed as the carriage is moved to draw a horizontal line. In addition, successive periods may be printed in successive vertical spaces or partially vertically superimposed to draw a vertical line. This is achieved by feeding the paper while the carriage is held at rest. Lines which are either horizontal or vertical are achieved by moving the carriage and feeding paper at the same time. Graphics patterns can be printed by combining these lines. Graphics printers with a matrix type font have achieved graphics printing by reducing a graphics image to be displayed to a collection of lines and then drawing the lines by repetitively striking the period, ".".
There are several major disadvantages to generating graphics printouts in serial printers with matrix type fonts by repetitive striking of the period character. First, the period character would wear much more quickly than the other characters. Secondly and equally disadvantageous is the time required to perform graphics printing. Also, software must be present either in the host computer, an interface or the printer to convert the bit addressable data generated by the computer to the vector based line graphics of the printer. As a result, serial printers with matrix type fonts have been less popular than dot-matrix type printers for graphics applications. This is in spite of the fact that the matrix type font printers produce higher quality characters and marks than characters and marks printed by a dot-matrix printer.
In addition to the above noted disadvantages, conventional matrix type font serial printers generate considerable noise when generating graphics printing and require large amounts of energy because the period character has to be struck repeatedly and the line feed mechanism constantly adjusted. As a result of the stress on the period character and the need to strike this character repeatedly to generate a graphics printout, the matrix type font serial printers have tended not to decrease in size or cost where graphics printing capabilities are required.
Accordingly, there is a need for a matrix type font printer and method for printing utilizing a matrix type font printer which generates bit addressable graphics at high speeds, with reduced energy consumption and without undue wear on any one of the character types.